Abstract: An apparatus and a method of compensating for an I/Q imbalance in a direct up-conversion system prevents the performance of the system from being deteriorated by efficiently compensating for an I/Q timing skew, an I/Q phase imbalance, and an I/Q gain imbalance by using a characteristic of an OFDM scheme in an Orthogonal Frequency Domain Multiple (Access) (OFDM(A)) system using a direct up-conversion scheme. According to the apparatus and the method of compensating for an I/Q imbalance in the direct up-conversion system of the present invention, an OFDM(A) system using a direct up-conversion scheme may efficiently compensate for I/Q timing skew, I/Q phase imbalance, and I/Q gain imbalance by using a characteristic of an OFDMA scheme, so that a performance of the system is prevented from being deteriorated.

Abstract: A method for adaptively driving data transmission and a communication device using the same are provided. The proposed method includes following procedures. Detection result is generated after detecting a receiving signal on a receiving path of the communication device. Driving parameter is generated according to the detection result. Finally, a transmitting signal on a transmitting path is adjusted according to the driving parameter.

Abstract: Described herein is a receiving apparatus and method for receiving signals in a wireless communication system, the signals including a dedicated channel estimation sequence, including a gain control means that controls the gain of a received signal, a channel estimation means that performs a channel estimation on the basis of a dedicated channel estimation sequence included in a received signal, a gain error correction means that corrects a gain error in the result of said channel estimation caused by said gain control means on the basis of the dedicated channel estimation sequence comprised in the received signal, and an equalizing means that performs an equalization on the received signal on the basis of the gain corrected channel estimation result.

Abstract: A method and system of adaptation of a linear equalizer using a virtual decision feedback equalizer (VDFE) are disclosed. In one embodiment, a method of adjusting a setting of a linear equalizer includes determining a change to a decision feedback equalizer (DFE) tap weight value of a predefined metric according to a data signal and an error signal (e.g., the change may be generated according to an average of a specified plurality of data signals and the error signal); using the change in the DFE tap weight value to algorithmically generate a modification in a linear equalizer setting; and adjusting the linear equalizer setting. The linear equalizer is located in a feed-forward path and/or a feedback path of data transmission. The linear equalizer may be located in a transmitter and/or a receiver. The linear equalizer may be a continuous time linear equalizer and/or a Finite Impulse Response (FIR) linear equalizer.

Abstract: A method includes receiving a signal transmitted by a transmitter, wherein the transmitter transmits with a transmit power and the signal includes a pilot signal transmitted by the transmitter with a fraction of the transmit power. The method further includes equalizing the received signal, determining a despread pilot signal based on the equalized signal, and determining the fraction of the transmit power based on the despread pilot signal.

Abstract: Embodiments are related to systems and methods for data processing, and more particularly to systems and methods for equalizing a data signal.

Abstract: The present invention relates to a method for generating impairment covariances for equalization in a receiver of a wireless communication system, as well as an covariance estimator, a receiver and a wireless communication system associated therewith, where the receiver is equipped with multiple antennas, and an impairment covariance matrix is used to calculate equalization weighting vector for signals transmitted by a transmitter, the method comprising the steps of: calculating a raw impairment covariance estimate between a first antenna and a second antenna of the multiple antennas on each of subcarriers allocated to the transmitter in frequency domain, transforming the raw impairment covariance estimates into time domain, masking the transformed impairment covariance estimates by a triangle window with a width defined by a maximum delay spread, determining a threshold based on the transformed impairment covariance estimates for the subcarriers and thresholding the masked impairment covariance estimates wit

Abstract: Embodiments are related to systems and methods for data processing, and more particularly to systems and methods for equalizing a data signal.

Abstract: A method for equalizing the received signal in communications based on filterbank multicarrier modulations and, more particularly, to such a method and system especially advantageous in situations where the channel frequency selectivity is exceptionally high. The method significantly improves the performance of traditional filterbank equalization algorithms based on finite impulse response filters at the output of the receive filterbank. Furthermore, the system consists of multiple parallel stages, the number of which can be tuned to achieve a good compromise between performance and computational complexity. Thanks to this modular structure, and to the fact that most of the architecture can be efficiently implemented using fast Fourier transforms, the system presents a very low computational complexity compared to more traditional equalizers for filterbank multicarrier modulations.

Abstract: Embodiments of the invention are generally directed to a configurable multi-mode driver and receiver. An embodiment of a communication system includes a communication channel, and a first device and a second device coupled with the communication channel. The first device includes a driver apparatus to drive data signals on the communication channel, the driver apparatus including circuits to receive and drive the data signals, where the circuits are configurable for termination resistance of the driver circuit apparatus, and each of the plurality of circuits is comprised of one or more circuit units, the circuit units being configurable for equalization control of the driver apparatus. The second device includes a receiver to receive data signals from the communication channel as an input. Either the first device or the second device includes configurable circuit elements to provide signal reflection control for the system.

Abstract: The present invention reduces the degradation in performance of one or more radio signals that are co-transmitted with a first radio signal from the same transmitting antenna in the same frequency channel and received by the same antenna due to multipath or other shared interference, where the one or more radio signals can be separated from the first radio signal. All received signals are coupled to the same adaptive array or adaptive filter to reduce multipath or other shared interference of the first radio signal, which reduces multipath and other shared interference in the other radio signals before they are separated and processed by their respective receivers, or the individual radio signals are separated before the first signal enters the adaptive array and coupled to a slave weighting network slaved to the weights of the adaptive array of the first signal to reduce interference in all the signals.

Abstract: For digital data transmitted using a vector signaling encoding, a rank-order equalizer cancels various channel noise such as inter-symbol interference. Further, rank-order units may be cascaded to achieve improved equalization over successive sample vector signals in a rank-order equalizer. Multiple rank-order equalizers further operate in parallel in a feed forward mode or in series in a feedback mode to provide a continuous vector signaling stream equalization.

Abstract: The method comprises receiving an input stream of symbols (x(i)) representing a phase change and magnitude of an RF signal, the magnitudes of the symbols are constant, the phase changes of the symbols encode digital information, and adjust the input stream of symbols to reduce inter-symbol interference. The adjusting iteratively determines a next symbol of the equalized stream (x?(n)) after receiving a next symbol of the input stream (x(n)) by multiplying the next symbol of the input stream (x(n)) with a next adjusting real number (a(n)), multiplying a previous symbol of the input stream (x(n?1)) with a previous adjusting real number (a(n?1)), the previous symbol being received before the next symbol of the input stream, and the next symbol of the equalized stream is computed from the multiplied next symbol and the multiplied previous symbol of the input stream.

Abstract: Requests are identified for equalization coefficients and a plurality of coefficient selections are tracked relating to the requests. A matrix is maintained within a grid space that is to represent the coefficients, the matrix representing one or more of the coefficient selections. The matric is adjusted within the grid space to obtain an adjusted matrix that is to accommodate selection of a particular coefficient outside the matrix. A final coefficient can be selected based on the adjusted matrix.

Abstract: Systems, methods, devices, circuits for transition based equalization.

Abstract: An apparatus comprising an equalizer circuit, a converter circuit and an adaptation circuit. The equalizer circuit may be configured to generate an intermediate signal in response to an input signal and a gradient value. The converter circuit may be configured to generate a digital signal comprising a plurality of symbol values, including a main cursor symbol value, in response to the intermediate signal. The adaptation circuit may be configured to generate the gradient value in response to a plurality of the symbol values before the main cursor symbol value, a plurality of symbol values after the main cursor symbol value, and an error value.

Abstract: Systems and methods are provided for adjusting gain of a receiver. Adaptation circuitry is operable to identify, based on a matrix representation of a receiver's output generated from horizontal and vertical sweeps of the receiver's output, an eye opening of the receiver's output. The adaptation circuitry is also operable to determine whether a size of the eye opening needs to be changed. When it is determined that the size of the eye opening needs to be changed, the adaptation circuitry is operable to generate a digital signal to change a gain setting of the receiver. When the signal at the receiver's output is under-equalized, the AC gain of the receiver is increased. When the signal at the receiver's output is over-equalized, the AC gain of the receiver is decreased.

Abstract: An equalizer configured to receive a data signal from a channel. The detector is coupled to the equalizer, and a calibration unit is coupled with the equalizer and the detector. The calibration unit is configured to jointly calibrate the equalizer and the detector using a metric subject to an entropy-preserving equalizer constraint.

Abstract: An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

Abstract: An OFDM receiver generates an initial channel impulse response in response to a received OFDM signal. The receiver determines the time span within the initial channel impulse response in which significant paths are present. An intermediate channel impulse response estimator identifies paths within the initial channel impulse response and generates an improved intermediate channel impulse response. A channel impulse response estimator performs a second non-linear process to generate a channel impulse response. An equalizer responds to the channel impulse response and the OFDM symbol to equalize the OFDM symbol. Metrics are generated that can be used for effectively stopping the second iterative non-linear process.

Abstract: A wireless charging in-band communication system includes a channel encoding for message error correction and detection. A modulation module performs biphase modulation for DC balanced signals and impedance switching to change reflected impedance seen by the source. A synchronization module prepends the message with a synchronization sequence having Golay complementary codes. A receiver module receives the message from the transmitter module. A preamble detection block has a Golay complementary code correlator used for message detection, synchronization, and equalization coefficient estimation and selection. A decoding module that performs biphase demodulation with error correction with a DC offset being estimated as the average value of the signal over the length of the message before channel decoding. The decoding module performs equalization, error correction and detection channel decoding.

Abstract: The present invention relates to a method of reducing equalizer complexity in communication systems, which also provides for reduced power dissipation. The method consists of reducing the number of channel responses expected by the equalizer by averaging sub-groups of all of the possible the channel responses chosen in a particular way.

Abstract: Techniques are disclosed for turbo decoding orthogonal frequency division multiplexing OFDM symbols. Techniques for combined turbo decoding and equalization are disclosed. The disclosed techniques can be implemented in receivers that receive wired or wireless OFDM signals and produce data and control bits by decoding the received signals.

Abstract: An apparatus and a method for estimating a channel in a broadband wireless access system. A receiving apparatus includes a first channel estimation filter having a tap coefficient which is channel-adaptively variable, the first channel estimation filter acquiring a channel impulse response by filtering received pilot symbols, a second channel estimation filter having a fixed tap coefficient, the second channel estimation filter acquiring a channel impulse response by filtering received pilot symbols, and a selector which selects the operation of one of the first and the second channel estimation filters according to channel correlativity.

Abstract: An ADC has ADC channels converting an analog input signal into an digital output signal in a time interleave manner; a channel combiner combining channel digital signals respectively output by the ADC channels and generate the digital output signal; an adaptive filter provided at one of the plurality of ADC channels; and a correction circuit detecting a skew error in the digital output signal, generating a coefficient of the adaptive filter according to the skew error for setting it in the filter. According to the skew error, in a first setting, the correction circuit sets the coefficient such that the adaptive filter phase-shifts to one direction a phase of the channel digital signal and, in a second setting, the correction circuit sets the coefficient such that the adaptive filter phase-shifts to an opposite direction and sets a coefficient with which the skew error is suppressed to a desired level.

Abstract: A receiver and a method for equalizing signals, the method includes: receiving input signals; sampling the input signals to provide oversampled samples; processing the oversampled samples to provide symbol spaced samples and to provide fractionally spaced samples that represent the oversampled samples; calculating taps of a fractionally spaced equalizer based on the symbol spaced samples; feeding the taps to the fractionally spaced equalizer; and filtering the fractionally spaced samples by the fractionally spaced equalizer to provide equalized samples.

Abstract: One embodiment relates to a receiver with both decision feedback equalization and on-die instrumentation. A clock data recovery loop obtains a recovered clock signal from an input signal, and a first sampler, which is triggered by the recovered clock signal, generates a recovered data signal from the input signal. A phase interpolator receives the recovered clock signal and generates a phase-interpolated clock signal. A second sampler is triggered by the recovered clock signal in a decision feedback equalization mode and by the phase-interpolated clock signal in an on-die instrumentation mode. Other embodiments and features are also disclosed.

Abstract: An apparatus includes an error sample generating circuit and an adaptation circuit. The error sample generating circuit is generally configured to generate error samples at a plurality of phases. The adaptation circuit may be configured to adjust one or more equalizer settings based upon a data sample and the error samples.

Abstract: Described embodiments include a receiver for a serial-deserializer or the like. The receiver has adaptive offset voltage compensation capability. The offset voltage is canceled by a controller in a feedback loop to generate a compensation signal depending on a data decision error signal or by timing signals used for clock recovery.

Abstract: Various embodiments described herein are directed to methods and systems for blind mode adaptive equalizer system to recover complex valued data symbols from the signal transmitted over time-varying dispersive diversity wireless channels. For example, various embodiments may utilize an architecture comprised of a bank of estimation units, a normalizing gain estimator, a DSP unit and a feedback shift register providing the equalizer feedback state vector. The estimation unit may be further comprised of a multiplicity of adaptive algorithms providing various filtered estimates of the data symbol to the DSP unit or providing the joint estimate of the transmitted data symbol.

Abstract: In order to solve a problem of achieving distortion compensation with high accuracy, a digital filter device includes a first distortion compensation filter unit for conducting distortion compensation of first waveform distortion included in an inputted signal through digital signal processing, a first filter coefficient setting unit for setting a filter coefficient of the first distortion compensation filter unit, a second distortion compensation filter unit for compensating second waveform distortion included in a signal outputted from the first distortion compensation filter unit, and a second filter coefficient setting unit for setting a filter coefficient of the second distortion compensation filter unit based on the filter coefficient set by the first filter coefficient setting unit.

Abstract: Provided are a transmission channel estimating device, a transmission channel estimating method, and a receiving apparatus. A transversal filter unit generates an estimated reception signal on the basis of a stored known signal sequence and tap coefficients, generates an error signal on the basis of a difference between a reception signal and the estimated reception signal, generates updated tap coefficients on the basis of the known signal sequence, the tap coefficients and the error signal, designates an effective section formed by a predetermined number of taps out of a plurality of taps in the transversal filter unit 2, and designates a first section and a second section set so as to include a center tap, wherein the generation of the estimated reception signal and the updated tap coefficients is performed by generating an estimated reception signal and updated tap coefficients for the first section and generating an estimated reception signal and updated tap coefficients for the second section.

Abstract: A sending and receiving system include a sending apparatus that performs a serial communication and includes a sending unit that sends a signal having a predetermined pattern; and a receiving apparatus that performs the serial communication and includes a receiving unit that provides the signal sent from the sending unit with an equalizing process depending on a setup value of an equalizer amount, a sampling unit that samples data obtained in the equalizing process by the receiving unit at a data rate higher than a data rate of the data, and a control unit that controls the setup value of the equalizer amount based on a change of the data corresponding to the predetermined pattern.

Abstract: A method, receiver and program for equalizing digital samples of a radio signal received over a wireless communications channel. The method comprises: receiving digital samples of the radio signal; calculating equalizer coefficients in the frequency domain; transforming the equalizer coefficients from the frequency domain to the time domain; and equalizing the digital samples in the time domain using the transformed time domain equalizer coefficients.

Abstract: Methods and systems adaptively equalizing an analog information signal, the method including sampling the analog information signal to provide analog samples including post-transition samples and steady-state samples, and equalizing the analog samples to produce equalized analog samples. The equalizing includes determining a difference between an average post-transition amplitude associated with at least one of the post-transition samples and an average steady-state amplitude associated with at least one of the steady-state samples, and adjusting an equalization coefficient to adjust the difference between the average post-transition amplitude and the average steady-state amplitude.

Abstract: Equalization techniques are provided for high-speed data communications and, more specifically, DFE (decision feedback equalizer) circuits and methods are provided which implement a high-order continuous time filter in a DFE feedback path to emulate structured elements of a channel response.

Abstract: An information processor has a CIR estimator configured to estimate channel impulse response of an input signal including a channel estimation sequence and a data sequence, based on the channel estimation sequence, an extended CIR calculator configured to calculate extended channel impulse response based on the channel impulse response estimated by the CIR estimator so that an extended CIR element padded with zeros is repeated a plurality of times in the extended channel impulse response, a Fourier transformer configured to convert the data sequence of the input signal into a frequency domain signal to calculate frequency response based on the extended channel impulse response, and an equalizer configured to perform equalization for removing a distortion from a propagation channel, based on the frequency domain signal and the frequency response.

Abstract: A method of operation of a wireless communication system includes: processing a received signal; calculating filter weights, by a filter weights estimation module, from the received signal; generating a corrected sequence, through a widely linear-single antenna interference cancellation (WL-SAIC) module, by applying the filter weights; calculating a channel estimation concurrently with the corrected sequence; and generating an adjusted data by an output equalizer including applying the channel estimation to the corrected sequence.

Abstract: A communication device includes multiple paths that are provided in the device and transmit signals; an adjuster that adjusts transmission characteristics to be a favorable state by adjustment of the waveform of the signals on the paths; and a controller that controls the adjustment of the transmission characteristics of the paths by the adjuster, identifies other path(s) that affects a path to be adjusted, and controls suppression of crosstalk due to the other path(s).

Abstract: An equalizer and a related equalizing method for equalizing signal reflection caused by a stub at a transmitting end are provided. The equalizer includes a summing device and a delay device. The summing device is utilized for adding a feedback delay signal to the input signal to generate the equalized signal. The delay device is coupled to the summing device, and utilized for delaying the equalized signal to generate the feedback delay signal. Wherein the delay device has a variable delay time and the variable delay time is a non-integer multiple of a bit time of the input signal.

Abstract: The present invention provides a method and apparatus for channel estimation when the amplitude of a received signal is hard-limited. A channel estimator computes amplitude estimates for the received signal based on the phase samples of the received signal. The amplitude estimates may comprise the expected values of the amplitude given the phase samples. The channel estimator then computes revised channel estimates based on the amplitude estimates and the phase samples. The process may be performed iteratively to refine the channel estimates during each iteration.

Abstract: The disclosed embodiments relate to the design of a linear equalizer that supports low-power, high-speed data transfers. In some embodiments, this linear equalizer contains a passive network that provides selective frequency peaking in a frequency range associated with a falling edge of a frequency response of the channel. It also includes a level shifter coupled between the channel and the passive network, wherein the level shifter is an active component that provides amplification and/or level-shifting. Moreover, the linear equalizer is designed so that power from the level shifter facilitates the selective frequency peaking of the passive network.

Abstract: Linear distortion and interference estimation using decision feedback equalizer coefficients. Processing of different respective groups of equalizer coefficients may be made to determine the residual frequency response of an equalizer and/or device in which the equalizer is implemented. Such an equalizer may be implemented within any of a number of respective communication devices including those operative within satellite, wireless, wired, fiber-optic, and/or mobile communication systems. A first group of equalizer coefficients corresponds to certain filtering characteristics of the equalizer and/or device in which the equalizer is implemented. The equalizer is implemented to process a signal to generate a second group of equalizer coefficients.

Abstract: A data equalizing circuit includes an equalizer configured to output data according to a control code; and a detection unit configured to divide the data into N number of calculation periods, count data transition frequencies for the N calculation periods, calculate dispersion values of the data transition frequencies for the N calculation periods, and output the control code corresponding to a largest dispersion value, in response to a counting interruption signal and a counting completion signal, wherein n is equal to or greater than 2, N is greater than n, and the data is divided to n number of unit intervals (UI), and wherein a phase shift of each of the calculation periods with respect to its corresponding UI is different from a phase shift of any of the other calculation periods with respect to its corresponding UI.

Abstract: A radio frequency equalizer includes a first resistor coupled to an input terminal, a second resistor coupled between the first resistor and an output terminal, a first capacitor, a first inductor, a first switch coupled to the input terminal, the first capacitor and the first inductor, a second switch coupled to the output terminal, the first capacitor and the first inductor, a second capacitor, a second inductor and a third switch coupled to the first resistor, the second resistor, the second capacitor and the second inductor. According to a control signal, the first switch selectively couples the first capacitor or the first inductor to the input terminal, the second switch selectively couples the first capacitor or the first inductor to the output terminal and the third switch selectively couples the second capacitor or the second inductor to the first resistor and the second resistor.

Abstract: A system for synchronizing IQ demodulators includes IQ demodulators, phase-controlling devices, a reference signal, a phase detector, and a control device. The phase-controlling devices are each associated with one of the IQ demodulators for outputting an output signal to its associated IQ demodulator having a phase controlled by the associated phase-controlling device. The phase detector is in communication with the output signals for determining whether the phase of any of the output signals is out-of-phase with a reference phase of the reference signal. The control-device is in communication with the phase-controlling devices programmed, internally or externally, to send a control signal to the associated phase-controlling device for any of the output signals which are out-of-phase with the reference phase of the reference signal so that the associated phase-controlling device synchronizes the phase of the output signal to being in-phase with the reference phase of the reference signal.

Abstract: The present invention relates to the field of MIMO wireless communication. Disclosed are a method for combining signals from multiple channels in a multi-antenna receiver and its apparatus. In the present invention, weight values corresponding to each antenna are calculated based on noise estimates or SNRs obtained from channel estimation, and a weighted combination is performed on each signal after channel equalization, which can effectively reduce impact of noises on signals and improve performances of receivers. Weight values are calculated for each subcarrier of each antenna based on noise estimates or SNRs, and a weighted combination is performed in subsequent step, which can further improve performances of OFDM receivers for a OFDM system.

Abstract: A method for data sequence detection includes generating a first sample stream, equalizing the first sample stream to generate a first equalized sample stream, and buffering the first equalized sample stream. The first sample stream is interpolated to generate a second sample stream. The second sample stream is equalized to generate a second equalized sample stream. In a first processing path, the samples of the buffered first equalized sample stream are filtered using a first noise predictive filter bank to generate a first set of noise sample streams. In a second parallel processing path, the samples of the buffered first equalized sample stream are interpolated using a second interpolation filter to generate an interpolated sample stream and the interpolated sample stream is filtered to generate a second set of noise sample streams. The first equalized sample stream and the second equalized sample stream are processed to generate adapted filter coefficients for the second interpolation filter.

Abstract: Apparatuses, methods, and other embodiments associated with adaptively determining equalizer setting for 10GBASE-KR transmitter are described. According to one embodiment, an apparatus for tuning an equalizer configured to undo the effects of a channel connecting a transmitter communicating to a receiver via a backplane includes a tuning logic configured to adaptively determine equalizer settings for the equalizer. The tuning logic includes a symmetric search logic configured to determine a desired boost setting for the equalizer, and an asymmetric search logic configured to determine a desired phase response for the equalizer.

Abstract: The present invention discloses a detection method, a receiver, and an apparatus in a multiple-input multiple-output single-carrier block transmission system. Through sorted QR decomposition (Sorted QR Decomposition, SQRD) decomposition based on a minimum mean squared error (Minimum Mean Squared Error, MMSE) criterion, an matrix inverse operation in minimum mean squared error equalization is avoided, and complexity is significantly reduced. In addition, through layer-by-layer soft interference cancellation detection after the SQRD decomposition and further iterative processing, better detection performance may be obtained. Especially, inter-stream interference suppression may be performed in first iteration.